Observation: Turnagain

Location: Lynx Creek Drainage

Date:

January 14, 2016 7:27pm

Observer:

W Wagner

Route & General Observations

Snowmachined up Lynx Drainage today to check on snow conditions South of Turnagain Pass. In general the snowpack is thinner in this area and we are concerned with buried weak layers in the pack that may exist here and not at the Pass itself. Highest elevation reached was 2,800′, point on the map below.

Red Flags

Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.

Observer Comments

Shallow wind slab avalanche (6-8" thick @ 4'000, W aspect) that looked to be triggered by a small piece of cornice that fell on the slope below. Photos below. This is VERY steep radical terrain sitting under a cornice - and, the type of small avalanche that would have high consequences considering the terrain. Also, the type of extreme/complex terrain that will, by nature, harbor some type of small slab here and there in the mountains when there is snow on the slopes.

Other than the above shallow wind slab, we did not find any other sign of instability.

Weather & Snow Characteristics

Please provide details to help us determine the weather and snowpack during the time this observation took place.

Weather

Valley fog that creeped up to 1700' - sunny and clear above. Calm winds and temps in the upper 20's F. A great day to be above the fog.

Snow surface

Crusty conditions exist up to 1,700' then turning to soft settled powder and dry snow above 2,000'. At 2,800' snowmachine penetration is 6-8" (without trenching) where boot penetration is 14-16".

Snowpack

Dug three pits over the course of today and yesterday.

Pit #1: 1,800', West 15 deg, HS 180cm. No results. BSH 1meter deep that did not react, even with a boot test.

Pit #2: 1,750, East 35 deg, HS 170cm. No results. BSH 1 meter deep that did not react as well.

Pit #3: 2,800', West 38 deg, HS 230cm. No results. No persistent grains types found in top 170cm of pack.

Bottom line: Snow pit tests showed good stability of the snowpack. We were able to find Buried Surface Hoar (BSH) in the more sheltered areas of the drainage but not on the steeper slopes. Additionally, A LOT of slopes avalanched during the Holiday Cycle and the debris is covered by 8-14" of snow that is littered about in avalanche terrain (the 'crush and flush'). This is all good news for good stability currently.

Photos & Video

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Shallow wind slab, West facing upper Lynx drainage

Wider angle view of the wind slab in Lynx

And, even a wider angle view - you can see the complex nature of this area

Snowpack at 1,800'

Snowpack at 2,800'

Great day to be above the fog!!

Location

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